Pfizer, BioNTech's Covid-19 drug shows encouraging results in early tests

With its other potential candidates still in the earliest stage of testing, Pfizer aims to open a large-scale study this summer but can't yet say which shot is best to include

The first of four experimental COVID-19 vaccines being tested by Pfizer and its German partner BioNTech showed encouraging results in very early testing of 45 people, the companies said Wednesday.

Study volunteers given either a low or medium dose, in two shots about a month apart, had immune responses in the range expected to be protective, when compared to some COVID-19 survivors, according to the preliminary results.

Side effects were typical for vaccines, mostly pain at the injection site and fever.

The report has been submitted for publication in a scientific journal but not yet reviewed.

With its other potential candidates still in the